Reflecting lens mount



July 6, 1943. R. E. BITNER REFLECTING LENS MOUNL` Filed Dec. 1s, 1941 2 Sheets-Sheet' l INVENTOR RALPH E. BITNER Y )L u? lATTORNEY REFLECTING LENS MOUNT Filed Dec. 13, 1941 -2 Sheets-Sheet 2 mvEN'roR RALPH E. BITNER ATTORNEY Patented July 6, 1943 REFLECTING LENS MOUNT Ralph E. Bitner, New York, N. Y., assignor to Remington Rand Inc., Buffalo, N. Y., a corporation of Delaware Application December 13, 194i, Serial No. 422,842

9 Claims.

This invention relates to binocular telescopes and particularly to structural design features for providing a dust free optical path.

The commercial prism binocular usually employs a sealed metal housing in which are mounted the reflecting prisms. However, the eyepiece lenses must be made movable to permit focusing and any continued eyepiece adjustment results in a pumping action which will change the air content within the enclosed housing and thereby introduce dirt and moisture to the inaccessible optical surfaces. The present design is an elort to reduce the evil eiects of this pumping action and provide other structural changes which will improve the life and performance of the telescope.

The invention resides in an inside enclosure which includes the inner face of the objective, the four reilecting mirrors and the inner face or" the eld lens of the eyepiece. A sack of moisture absorbing material is placed at the entrance of this enclosure and structural means is provided to adjust the angular position of the reecting units to achieve parallelism without admitting air into the enclosure. Focusing is performed by the adjustment of the eye lens of the eyepiece.

One of the objects of the present invention is to improve the structural design of. a reflecting binocular to include an inner enclosure for the elimination of moisture and dirt from the interior optical surfaces.

Another. object of the invention is to improve the design of the reilecting` units so that they may be no larger than reecting prisms of similar utility and have considerably less weight.

Another object of the invention is to incor-4 porate a moisture absorbing substance between the internal enclosure and the external housing to keep moisture away from the optical surfaces.

Another object of the invention is to improve the adjustable means for aligning the reflecting surfaces so that adjustment may be made while observing a test object.

Other objects and structural Adetails ofv the invention will be apparent from the following description when read in connection with the accompanying drawings, wherein Fig. 1 is a sectional view of one side of a refleeting binocular showing the two reectirig structures and the objective;

Fig. 2 is a sectional view taken along line 2-2 of Fig. 1 and shows the adjustable reflector mounting;

Fig. 3 is a side View of part of the inner enclosure with the eyepiece in section; and

Fig. 4 is a sectional view taken along line il-f.. of Fig. 2 and shows the spring mounting of one of the reecting units.

Referring now to Fig. l, an outside housing l@ is employed, as usual, to act as a structural basis for mounting all the other components. A telescope objective lens il is n ounted in the forward end of the housing and s held in place by a clamping ring l2. At the eyepiece end of the housing, a cover plate i3 of conventional design is employed to close the opening through which the reector unit is assembled. An auxiliary mounting plate ill (see Fig. 3) is secured adjoining the cover plate to hold a focusing mount lli in which is clamped the ocular cornponent l5 of the eyepiece.

The inner enclosure which includes mountings for the reflector units and the eld lens is secured to a shelf ll which fits snugly into the housing l@ and is bolted to three offset portions i8, 2li, and 2l cast integral with the housing.

Three 'holes are cut in the shelf as indicated in Fig. 2 and into one of these a thin walled conc shaped tube 22 is secured. This tube extends A drical tube Si is securely mounted (Fig. 3) a f almost to the objective ii and near the end thereof contains a plurality of holes About an inch from the objective end there is formed a series of annular corrugations 26.

In the intervening space between the inside of the housingv and the outside of 4the tube 2f; an annular sack 2S is positioned which contains a, small quantity of moisture absorbing material such as calcium chloride or silica gel. The inner wall 25 of the sack ls made of flannel or similar cloth, which will retain the absorbing material while at the same time allowing moisture to gradually work through from the enclosure. The outside wall 2l of the sack 25 is made of varnished cloth, which is air-tight under all normal Conditions of variable atmospheric pressure, The objective edge of the sack is held against the inside wall of the housing EE by a spring wire 2B, while the other edge is held in contact with corrugations 25 of the tube 22 by a second spring Wire titi.

In another hole in the shelf l? a short cylinthe eld lens 32 of the eyepiece combination is mounted in the lower end of this tube by the usual retaining means.

Two reecting units `33 and 34? are positioned over the remaining openings in a manner similar to the placing of the porroprisms in the well known prism binocular. Each lreecting unit consists of a thin-walled support on which two reflecting discs 3/5 may be mounted. These reflecting discs may be made of any suitable materials, the preferred type being glass with a reflecting lm of sputtered aluminum or rhodium. The correct shape of these discs is an ellipse with the major axis equal to 1.414 times the minor axis. The discs 35 are mounted in such a manner as to form a. hermetically sealed joint between the edges of the disc and the opening in the shell.

For the purpose of alignment, each shell is pivoted on two knife edges 36 (Figs. 1 and 3) which flt into slots in the shelf I'I. the shell is formed with a triangular plate 31,

One side ofy cast integral with the shell, and a spring and colt combination 3B holds this plate resiliently stressed toward the shelf I1. .On the other side of the shell, a similar triangular plate d is employed to positively position the shell in alignment and make the optical paths through-the binocular parallel to each other. In order to -make the aligning operation easy and convenient, two machine screws 4I and 42 are set with their heads directed toward the eye piece end of the instrument so that a screw driver may make the adjustment while looking through the telescope at a test object.

In order to make the enclosure air-tight at this point and still have a small degree of adjustment, gaskets 43 of sponge rubber are placed under the reflecting shells 33 and 34 and cemented in place when the instrument is first assembled.

As the light traverses the optical system, it rst passes through the objective Il and enters the inner enclosure. Then it is successively reflected to absorb and retain moisture. large number of such chemicals are available.

While I have described what `I consider to be highly desirable embodiments of my invention, it

4is obvious that many changes in form could be made without departingl from the spirit of my invention, and I, therefore, do not limit myself tothe exact form herein shown and described, nor tol anything less than the whole of my invention as hereinbefore set forth, and as hereinafter claimed. I

What I claim as new, and desire to secure by Letters Patent, isz, f l

1. In a reflecting telescope' of the class described, a supporting housing, an enclosure within said housing comprising two cylindrical tubes and a quadruple reflecting assembly, an objective lens adjacent the open end of one of said tubes and a field lens of an eyepiece closing the open end of the second of said tubes, said first tube having one or more perforations in the walls thereof, a moisture-pervious fabric covering said perforations, and an anhydrous moisture absorbing material held in contact with said pervious fabric by a flexible non-pervious fabric.

2; In a reflecting telescope of the class described, a supporting housing, an enclosure within said housing comprising two cylindrical tubes and a reflecting assembly, an objective lens adjacent the openV end of one of said tubes and a field lens of an eyepiece closing the open end of said second tube, said reflecting assembly comby the four reflecting 'surfaces 35, all within the i y closure since the only reason for such movement resides in the small changes of atmospheric pressure which occur on the earths surface. If the instrument is taken aloft in an airplane, however, the pressure change will be sufficient to cause a considerable volume of air to move out of the enclosure on going up and to move back again when returning to sea-level. For these conditions the outer sack fabric 2l may be made of airpervious material, the saine as theinner fabric 26 and the air is then permitted to move from the enclosure to the housing with little resistance.

It should be noted that on making a the dry dust free air is first removed from the inner enclosure and moves to the intervening flight,

space between the enclosure and the housing.

When landing this same dry air is drawn back into theenclosure along with a percentage of outprising two adjustable shells, each of said shells supporting two reflecting discs, said first tube having one or more perforations in the Walls thereof, a moisture-pervious fabric covering said perforations, and an anhydrous moisture absorbing material held in contact with said pervious fabric by a flexible non-pervious fabric.

scribed, a supporting housing, an enclosure within said housing comprising .two cylindrical tubes and a quadruple reflecting assembly, an objective lens adjacent the open end of one of said tubes and a field lens of an eyepiece closing the open end of the second of said tubes, saidnenclosure having one or more openings in the Walls thereof for .equalizing pressure changes,` a moisturepervious fabric covering said openings, and ananhydrous moisture-absorbing material held in contact with said pervious fabric by a exible non-pervious fabric.

4. In a, reflectingl telescope of the class described, a supporting housing, an enclosure witlrin said housing comprising two cylindrical tubes and a reflecting assembly, an objectivelens adjacent the lopen end of one of said tubes and one of the components of an eyepiece closing tlie open end of said secondtube, said reflecting assembly comprising two adjustable shells, each of said shells supporting two reflecting discs, said.

enclosure having one -or more openings in the walls thereof for equalizing pressure changes, a moisture-pervious fabric covering said openings, and an anhydrous moisture-absorbing materi l held in contact with said pervious fabric by flexible nonpervious fabric.

`5. In a reflecting telescope of the class .de-

scribed, a supporting housing, an enclosure within said housing comprising two cylindrical tubes and aquadruple reflecting assembly, an objective lens adjacent the open end of one of said tubes and a field lens of an eyepiece closing the open end of the second of said tubes, said first tube having one or more openings in the walls 3. In `a reflecting telescope of the class dey thereof, a container having walls of exible fabric disposed about said first tube to cover said orenings, an anhydrous moisture absorbing material Within said container, and resilient mounting rings for holding said container in position, said container walls comprising a moisture-pervious fabric adjoining said openings and an impervious fabric opposite said pervious fabric.

6. In a reecting telescope of the class described, a supporting housing, an enclosure within said housing comprising two cylindrical tubes a quadruple reiiecting assembly, an objective lens adjacent the open end of one of said tubes and a leld lens of an eyepiece closing the open end of the second of said tubes, said rst tube having one or more perforations' in the wall thereof, a moisture-pervious annular sack disposed about said iirst tube covering the perforations therein and an anhydrous moisture-absorbing material within said sack.

7. In a reflecting telescope of the class described, a supporting housing, an enclosure with` in said housing comprising two cylindrical tubes and a reflecting assembly, an objective lens adjacent the open end of oneof said tubes and a field lens of an eyepiece closing the open end of said second tube, said reflecting assembly comprising two adjustable shells each of said shells supporting two reflecting discs, said rst tube having one or more perforations in the Walls thereof, a. moisture-pervious annular sack disposed about said first tube covering the perforations therein and an anhydrous moisture-absorbing material within said sack.

8. In a. reflecting telescope of the class described, a supporting housing, an enclosure within said housing comprising two cylindrical tubes and a reiiecting assembly, an objective lens adjacent the open end of one of said tubes and one of the components of an eyepiece closing the open end of said second tube, said reflecting assembly comprising two adjustable shells, each of said shells supporting two reflecting discs, said enclosure having one o r more openings in the Walls thereof for equalizing pressure changes, a moisture-perviene annular sack disposed about said first tube covering the perforations therein and an anhydrous moisture-absorbing material Within said sack.

9. 1n a reecting telescope of the class described, a Supporting housing, an enclosure witifi-a in said housing comprising two cylindrical tubes and a quadruple `reflecting assembly, an objective lens adjacent the open end of one of said tubes and a eld lens of an eyepiece closing the open end of the second of said tubes, said first tube having one or more openings in the walls' thereof, a container having walls of iiexible airperious fabric disposed about said rst tube `to cover said openings, an anhydrous moisture-absorbingmaterial within said container, and resilent mounting rings for holding said container imposition.

RALPH E. BIINER. 

